Molecular tests for malaria that can be performed with unprocessed samples

可以使用未处理的样本进行疟疾分子检测

• 批准号: 8110641
• 负责人: Huimin Kong
• 金额: $ 26.96万
• 依托单位: BIOHELIX CORPORATION
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-15 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8110641
• 关键词: Address; Anti-malarial drug resistance; Antimalarials; Biological Assay; Blood; Cause of Death; Chemistry; DNA; DNA amplification; Detection; Development; Diagnostic; Diagnostic tests; Gold; Immunoassay; Laboratories; Lateral; Malaria; Microscopy; Molecular; National Institute of Allergy and Infectious Disease; Nucleic Acids; Parasites; Patients; Performance; Pharmaceutical Preparations; Phase; Plasmodium; Plasmodium falciparum; Population; Relative (related person); Resistance; Resources; Rural; Sampling; Small Business Innovation Research Grant; Staging; Technology; Testing; Whole Blood; asexual; base; fighting; helicase; inhibitor/antagonist; internal control; manufacturing process; pathogen; public health relevance

DESCRIPTION (provided by applicant): This SBIR-AT-NIAID Phase I application addresses the problem of malaria diagnostics in resource- limited settings. BioHelix, has developed an isothermal nucleic acid amplification chemistry called helicase dependent amplification (HDA) that is tolerant of the DNA amplification inhibitors present in whole blood. This proposal will focus on the application of this technology to the detection of malarial asexual parasites without nucleic acid extraction. Based on our preliminary results, the expected sensitivity of the species-specific molecular test (~100 nucleic acid copies/5L blood) better than that possible with current rapid tests for asexual stages (200 copies of parasite/5L blood). Our specific objectives for this 2-year-long project are: 1. Develop an HDA assay to detect P. falciparum, P. vivax, P. ovale, and P. malariae. 2. Develop competitive internal controls (CIC) for the species-specific assay, as well as a 2-plex assay to detect the CIC with the targets in whole blood. 3. Develop manufacturing processes for the proposed assay kit that will enable field-use of the technology. 4. Evaluate the performance of the assay relative to the gold-standard tests. 5. Obtain CE marking for the assay. 6. Submit a pre-IDE to FDA as a preliminary step to seeking FDA clearance for the test. PUBLIC HEALTH RELEVANCE: As malaria is the leading cause death in endemic regions, the current treatment approach is not based on laboratory, or microscopy testing because establishing quality-assured microscopy in rural and resource- poor settings is difficult. The liberal use of anti-malarial drugs that results from such practices presents a problem in that resistance to first line drug treatments is wide-spread. This SBIR-AT-NIAID proposal focuses on the development of a species-specific for the detection of Plasmodium in blood. More sensitive, species- specific, and stage-specific diagnostic tests will help focus drug treatment, and may slow the spread of anti- malarial drug resistance in the pathogen population. Based on our preliminary results, the expected sensitivity of the species-specific DNA test (~100 nucleic acid copies/5L blood) will be better than that possible with current rapid tests for asexual stages (200 copies of parasite/5L blood). A more sensitive test that can be performed in the field near patients would greatly enhance malaria fighting activities. We anticipate tests in the range of $7-$10 for the HDA tests should be possible, if total test volumes reach 200,000.

描述（由申请人提供）：该 SBIR-AT-NIAID 第一阶段申请解决了资源有限环境中的疟疾诊断问题。 BioHelix 开发了一种称为解旋酶依赖性扩增 (HDA) 的等温核酸扩增化学物质，它能够耐受全血中存在的 DNA 扩增抑制剂。该提案将重点关注该技术在不提取核酸的情况下检测疟疾无性寄生虫的应用。根据我们的初步结果，物种特异性分子测试（约 100 个核酸拷贝/5L 血液）的预期灵敏度优于当前无性阶段快速测试（200 个寄生虫拷贝/5L 血液）的灵敏度。我们这个为期两年的项目的具体目标是： 1. 开发一种 HDA 检测方法来检测恶性疟原虫、间日疟原虫、卵形疟原虫和三日疟原虫。 2. 开发用于物种特异性测定的竞争性内部对照 (CIC)，以及用于检测全血中目标 CIC 的 2 重测定。 3. 开发拟议检测试剂盒的制造工艺，以实现该技术的现场使用。 4. 相对于金标准测试评估测定的性能。 5. 获得检测的 CE 标记。 6. 向 FDA 提交预 IDE，作为寻求 FDA 测试许可的初步步骤。 公共卫生相关性：由于疟疾是流行地区死亡的主要原因，目前的治疗方法并非基于实验室或显微镜检测，因为在农村和资源匮乏的地区建立有质量保证的显微镜检查很困难。这种做法导致抗疟疾药物的大量使用带来了一个问题，即对一线药物治疗的耐药性广泛存在。 SBIR-AT-NIAID 提案的重点是开发一种用于检测血液中疟原虫的物种特异性药物。更灵敏、物种特异性和阶段特异性的诊断测试将有助于集中药物治疗，并可能减缓抗疟疾药物耐药性在病原体群体中的传播。根据我们的初步结果，物种特异性 DNA 测试（约 100 个核酸拷贝/5L 血液）的预期灵敏度将优于当前无性阶段快速测试（200 个寄生虫拷贝/5L 血液）的灵敏度。可以在患者附近现场进行的更灵敏的测试将大大增强抗击疟疾的活动。如果总测试量达到 200,000 次，我们预计 HDA 测试的费用将在 7-10 美元之间。